For area the square hectometer (hm2) is a common unit. It is more commonly known by the name of hectare (ha), meaning 100 ares (100 a). The are is a measurement of area the size of 1 decametre by 1 decametre, which is 10 metres by 10 metres. Hence 100 ares equals an area with dimensions 100 m by 100 m — 1 hectometre by 1 hectometre, the square hectometre — equalling 10,000 square metres (10,000 m2)